1. Field of the Invention
The present invention relates to a method and apparatus for observing traffic information of multimedia communications having various speeds including audio, image and data communications and altering a communication network configuration based on the observed results.
2. Description of the Related Art
It is difficult to forecast traffic information of multimedia communications of nowadays having various speeds including audio, image and data communications. Therefore, routinely altering a logical communication network configuration (logical link) based on data observed in a certain time intervals and service contract contents can improve a utilization ratio of a communication network.
JPA 4-13343 (a prior art reference) entitled xe2x80x9cA link capacity control system of learning typexe2x80x9d discloses one of such centralized communication network observation and control systems. The system of the prior art observes the amount of calls in an individual link which connects switches, and determines an allocation ratio of the capacity in each link based on an observed amount while keeping the total capacity within a capacity of the physical line which accommodates the link.
The system includes a lot of input and output signal lines and a correct answer output signal line. Also provided is a function-learning device capable of altering a relation between an input signal and an output signal corresponding to the input signal by altering a combination of values in inner registers. A function for assuming a traffic loss ratio on the basis of an observed value related to a load applied to a link and the capacity of the link is generated by learning observed values obtained from a running communication network using the function-learning device. An optimum link capacity allocation is searched and determined while estimating the link capacity allocation based on the output value of the function.
The above-mentioned conventional communication network observation and control system, however, has no concept related to multi-layered structure in observation object and control object though most of the current communication networks are multi-layered. It is difficult to anticipate a state of an upper layer from a state of a lower layer since each layer is provided with a resending control, bandwidth control and error control in consideration of the whole communication network. Therefore, it is required to observe the traffic load and real throughput at the upper layer and control the lower layer in accordance with the observed items, the service contract contents and a state of the lower layer in order to improve the utilization ratio of the network. The prior art reference, however, does not teach this point.
It is also a disadvantage that only the link capacity is regarded as an object to control. A total allocated link capacity varies in accordance with a position (physical communication network) and order for allocating a link capacity as in the case of a three-dimensional bock problem famous as a combination problem. The utilization ratio of the communication network can be improved by altering the link path of the lower layer within an allowable range in consideration of the service contract contents and the contents of the control mechanism arranged in the upper layer. The prior art reference, however, does not teach this point.
In order to overcome aforementioned disadvantages, the present invention has been made and accordingly, has an object to provide a method and apparatus for observing and controlling a communication network even when the communication network is a multi-layered communication network.
Another object of the present invention is to provide such method and apparatus which satisfies the quality of service.
A further object of the present invention is to provide such method and apparatus which improve a utilization ratio of a communication network.
According to a first aspect of the present invention, there is provided a method for observing and controlling a multi-layered communication network, comprising steps of storing control contents for each layer; observing traffic information of each link which belongs to an upper layer; storing the traffic information observed and related information for each link; altering a route in a lower layer for each link and capacity for each link based on the observed traffic information for each link, related information for each link and the control contents for each layer.
The altering step may be started when an amount in the traffic information exceeds a predetermined threshold for a predetermined period.
The altering step may use a heuristic algorithm based on a rule of thumb.
According to a second aspect of the present invention, there is provided an apparatus for observing and controlling a multi-layered communication network, comprising: means for storing control contents for each layer; means for observing traffic information of each link which belongs to an upper layer; means for storing the traffic information observed and related information for each link; means for altering a route in a lower layer for each link and capacity for each link based on the observed traffic information for each link, related information for each link and the control contents for each layer.
The altering means may be activated when an amount in the traffic information exceeds a predetermined threshold for a predetermined period.
The altering means may use a heuristic algorithm based on a rule of thumb.
The traffic information may include at least one of a link utilization ratio, a delay time and an abolition rate.
The traffic information may include a throughput of packets.
The related information may include service contract contents, a current link capacity, and a current link route.
The service contract contents may include contracted quality of service, a contracted link capacity and a priority for ensuring a link capacity.
The control contents for each layer may include a presence/absence of a resending control, a latency to resending, and a confirmation/non-confirmation type.
Other features and advantages of the invention will be apparent from the following description of the preferred embodiments thereof.